The ON-SP5 Survival bowie is 15 1/8" in overall length with a ten inch blade, full flat grind and a clip point tip. The ON-SP11 Spec Plus Bolo is also 15 1/8" overall with a ten inch blade and full flat grind. It has a much wider tip than the Survival bowie and has a deep blade curvature. The ON-SP10 Spec Plus Marine Raider bowie is 15" in overall length with a 9 5/8" long blade. It has a shallow sabre flat grind. The Ontario Spec Plus Khukuri is 17" in overall length with a twelve inch blade. It has no primary grind. All blades are made from 1095 and are uniformly hardened. The have a black epoxy powder coating, black grooved polymer handles with lanyard hole and all come with a black Cordura and leather belt sheath.
The Survival bowie and Bolo work well on light brush work, and are decent cutters due to the full flat grinds and are nice and efficient being light in the hand and thus don't induce a heavy rate of fatigue. They however lack the power for heavy chopping and tend to just bounce of hard woods. The Marine Raider bowie does much better on that class of wood as it is heavier in the hand and allows much more power to be built up on the swing. Russ Slate (Rusty on Bladeforums) who owns these knives sharpened the top of the clip point on the Marine Raider bowie and it thus works well as a heavy cutter on hard materials, and it also acts to increase the penetration of the tip. The khukuri is essentially useless as a knife as it is too thick and can not effectively do any cutting well. The grips however can be a problem as I found them decently abrasive and the end hook has took sharp a curvature. The double guard on the Marine Raider bowie also limits utility work.
The blades were used along side some khukuris from Himalayan Imports over a variety of tasks, the description of which can be seen on the following page :
In short, the Bolo and Survival bowies were efficient cutting tools, and decent short machetes. The Marine Raider bowie didn't cut as well but was a much better chopping tool having much greater heft in hand. The khukuri had little chopping or cutting ability due to lack of a primary grind and far too thick and obtuse edge.
In regards to durability, the Survival bowie snapped under a light load, while the Bolo took a permanent bent in the handle under similar conditions, one blade was too hard and the other too soft. Other problems regarding brittle failure have been noted with other Ontario blades, specifically two machetes.
Quite some time after the above was review was written the Marine Raider bowie was reground to enhance its performance and illustrate the kind of effect that geometry has on cutting and chopping ability [ ref] .
The Marine Raider Bowie, had a rather thick and obtuse edge bevel, about 20 degrees near the choil, more obtuse towards the tip maxing out at about 25 degrees. Cutting up small wood (2.5-3.5") the bowie had 63 +/- 3 % of the chopping ability of the Wildlife hatchet from Gransfors Bruks.
Aside from penetration, the obtuse edge and primary grind induced a relatively high tendancy to glance for the bowie. The end hook is also too sharp atoo drive off from, without generating excessive pressure on the pinky. A bit of oil on the handle also saw the blade becoming very unstable in hand, which lowered performance as chops needed to be less energetic to keep a hold of the knife. The hatchet is not as strongly effected by such grip conditions as the chopping performance doesn't depend as much on the followup drive after the blade hits the wood.
On method, this was chopping felled wood at about waist height using full force swings. Various contact areas along the length of the blade on the bowie were used and the optimum performance was obtained close to the choil. Further out on the blade the speed increased, but there were leverage disadvanatges which didn't allow the blade to be drove deep into the wood. Chopping style of course is an influence here.
In regards to cutting ability, whittling six points on one inch hardwood dowels, the bowie took 29 +/- 3 cuts to make a point. The blade does not bite in deeply into the wood and the thick profile forces a lot of splitting of the chips. The Bruks hatchet easily outperforms the bowie carving much larger chips, with less effort, it takes about ~15 slices to make a point.
A one inch belt sander created a 12-13 degree edge bevel. The primary grind was lightly ground, not enough to significantly remove any metal, but just to get a feel for how much work it would take to put a full height flat grind on the blade (a lot). After the shaping 15 micron sandpaper to remove the burr and do a preliminary sharpening. After 20 strokes per side the blade would shave roughly. Five Micron SiC paper was used to further hone the edge which was finished with some stropping on leather loaded with CrO, the blade would now shave smoothly. Because the leather gave somewhat under the sandpaper, this introduced a secondary edge bevel of about 15 degrees over the last 0.04" of the edge.
On the hardwood dowel, the bowie showed a huge change in bite, requiring 14 +/- 1 cuts, a performance increase of about 100%. Note that this result is a little skewed because of the effect of fatigue, but only I would estimate by a few percent.
The Marine Raider bowie also showed a large increase in chopping ability. Through cutting 57 sections of some small sticks (502 chops in all), the bowie had 95 +/- 4 % of the chopping ability of the hatchet, about a 50% increase in chopping performance.
Aside from the increase in penetration, the problem with glancing was significantly reduced, and shallower angles of cut were now possible. After the chopping the edge would even still scrape a little arm hair so there were no durability issues. Note that one out of every ten or so cuts was through a knot.
In more detail, while the knife could still slice paper after the chopping, although it had to be within 0.5 inches of the holding point to start the cut. The blade requires about 3.5 cm to cut through 1/4" poly under a 1000 g load. Under magnification damage on the order of 0.05 - 0.1 mm, or 50-100 micron is noted, impaction / deflection.
A quick session of stropping (10 passes per side) on CrO loaded leather increases the performance of the blade on the poly about 75%. Another session does little to increase the performance indicating that the edge is in a near optimal state of alignment, however with a significant amount of wear, and the degraded sections (1-2 every mm), are giving a false sense of aggression when the edge is checked with my thumb.
In regards to the exact edge angles used, what is optimal will depend on the wood being cut as well as technique used. As technique improves and wood gets softer, angles can be lowered without a loss in functional durability.
Comments can be emailed using cliffstamp[REMOVE]@cutleryscience.com , and seen in the following ARCHIVED thread on Bladeforums :
More information can be obtained at the Ontario knife company website.
| Last updated : | Fri Jun 25 01:20:45 NDT 2004 |
| Originally written: | Thu May 6 09:39:02 NDT 1999 |